Blame it on animal spirits

Most, probably, of our decisions to do something positive, the full consequences of which will be drawn out over many days to come, can only be taken as the result of animal spirits — a spontaneous urge to action rather than inaction, and not as the outcome of a weighted average of quantitative benefits multiplied by quantitative probabilities.

— John Maynard Keynes, The General Theory
of Employment, Interest and Money
(1936)

Animal Spirits

— Jacket art by Edward Koren from
Akerlof & Shiller,
Animal Spirits (2009)